Washing machine having drying function and method for controlling the same

ABSTRACT

A washing machine having a drying function and a method for controlling the same. The washing machine includes a tub for containing wash water; a drum rotatably placed in the tub for containing laundry, and provided with through holes for circulating the wash water or air therethrough; a drying device provided with a circulation fan and a heater for drying the laundry in the drum; and a pumping device for pumping the wash water in the tub so that the wash water in the tub is circulated into the drum or heated by the air passing through the drying device, and is then circulated into the drum. The washing machine performs washing of laundry without any additional heater for heating the wash water, thereby having low production costs and a simple structure of the tub.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a washing machine having a drying function, which performs a drying operation as well as a washing operation, and more particularly to a washing machine having a drying function, in which wash water is heated by a drying device without an additional heater for heating the wash water, and a method for controlling the washing machine.

2. Description of the Related Art

Generally, washing machines are apparatuses for eliminating contaminants from laundry using actions of a detergent and wash water, and are divided into an agitator type washing machine, a pulsator type washing machine, and a drum type washing machine.

The agitator type washing machine washes laundry by rotating a washing rod, protruded from the center of a tub, in the clockwise or counterclockwise direction, the pulsator type washing machine washes laundry using friction between a water current and the laundry by rotating a circular pulsator, formed on the bottom of the tub, in the clockwise or counterclockwise direction, and the drum type washing machine washes laundry by putting wash water and a detergent into a drum, provided with lifters protruded therefrom and rotatably placed in the tub, and rotating the drum.

Recently, in order to increase washing capacity, washing machines having a drying function, which comprise a heater for heating wash water and a drying device for drying laundry, have been increased in number.

FIG. 1 is a longitudinal sectional view of a conventional washing machine having a drying function.

As shown in FIG. 1, the conventional washing machine comprises a casing 2, a tub 4 installed in the casing 2 for containing wash water (w), a drum 10 rotatably placed in the tub 4 for containing laundry (m), a motor 20 for rotating the drum 10, a heater 22 installed at the lower part of the inside of the tub 4 for heating the wash water (w) in a washing or rinsing mode, and a drying device 30 installed outside the tub 4 for circulating and drying air in the tub 4 in a drying mode.

A water supply device 6 for supplying a detergent or the wash water (w) to the inside of the tub 4 in the washing or rinsing mode is connected to the upper part of the tub 4, and a drainage device 8 for discharging the wash water (w) from the inside of the tub 4 to the outside is connected to the lower part of the tub 4.

A heater-receiving portion 5 for receiving the heater 22 is formed in the bottom of the tub 4, and a sealing member for preventing water leakage between the heater 22 and the tub 4 is installed on the tub 4.

The heater 22 for heating the wash water (w) includes a heating portion 23 received in the heater-receiving portion 5 of the tub 4 for generating heat when power is supplied thereto, and a power-supply portion 25, to which an electric wire 24 is connected so that the power is supplied to the heating portion 23.

The drying device 30 includes a drying duct 36 containing a heater 32 and a circulation fan 34 for discharging hot air to the inside of the tub 4, a condensing duct 38 for guiding the air in the tub 4 to the drying duct 36, and a water supply nozzle 40 formed at one side of the condensing duct 38 for spraying cooling water to the inside of the condensing duct 38 so that moisture in the air passing through the condensing duct 38 is condensed.

Hereinafter, the operation of the above conventional washing machine having a drying function will be described in detail.

First, the water supply device 6 in the washing or rinsing mode supplies the wash water (w) to the inside of the tub 4, and the motor 20 is operated to rotate the drum 10, thereby causing the laundry (m) in the drum 10 to be washed.

In the washing or rinsing mode, power is supplied to the heater 22 for heating the wash water (w), and the heater 22 heats the wash water (w). The washing or rinsing capacity of the laundry (m) is improved using the heated wash water (w).

When the above washing or rinsing mode is terminated, the drainage device 8 discharges the wash water (w) from the tub 4 to the outside of the washing machine.

Thereafter, the dehydrating mode is performed. Here, when the motor 20 rotates the drum 10 at a high speed, the laundry (m) is rotated together with the rotation of the drum 10, thereby being centrifugally dehydrated.

The motor 20, when operated, rotates the drum 10 so that the laundry (m) is dried, turns on the heater 32 and the circulation fan 34, and supplies cooling water through the water supply nozzle 40.

When the circulation fan 34 is turned on, the air in the drum 10 and the tub 4 passes through the condensing duct 38 and is condensed by the cooling water so that the air has a low humidity, passes through the drying duct 36 and is heated by the heater 32 so that the air has a high temperature and a low humidity, and is circulated into the drum 10 so as to dry the laundry (m) in the drum.

The conventional washing machine having the drying function separately comprises the heater 22 for heating the wash water (w) in the washing or rinsing mode and the drying device 30 for drying the laundry (m), thereby having high production costs.

Further, since the heater-receiving portion 5 is installed in the bottom of the inside of the tub 4, and the heater 22 for heating the wash water (w) is installed on the tub 4, the conventional washing machine has complicated structures of the tub 4 and the heater 22, and an assembly process including various steps.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a washing machine having a drying function, which comprises one heater for drying laundry and heating wash water, thereby having low production costs.

It is another object of the present invention to provide a washing machine having a drying function, which has simple structure and assembly process.

It is yet another object of the present invention to provide a method for controlling a washing machine having a drying function, which controls wash water such that the wash water is circulated into a drying device or is sprayed to the inside of a drum, thereby improving washing or rinsing capacity.

In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a washing machine having a drying function comprising: a tub for containing wash water; a drum rotatably placed in the tub for containing laundry, and provided with through holes for circulating the wash water or air therethrough; a drying device provided with a circulation fan and a heater for drying the laundry in the drum; and a pumping device for pumping the wash water in the tub so that the wash water in the tub is circulated into the drum, or is heated by the air passing through the drying device and circulated into the drum.

In accordance with another aspect of the present invention, there is provided a washing machine having a drying function comprising: a tub for containing wash water; a drum rotatably placed in the tub for containing laundry, and provided with through holes for circulating the wash water or air therethrough; a drying device provided with a circulation fan and a heater for drying the laundry in the drum; and a pumping device for pumping the wash water in the tub so that the wash water in the tub is heated by the air passing through the drying device, and is then circulated into the drum.

Preferably, the drying device may include a drying duct containing the heater and the circulation fan for discharging hot air to the inside of the tub; a condensing duct for guiding the air in the tub to the drying duct; a water supply nozzle for spraying cooling water to the inside of the condensing duct so that moisture in the air passing through the condensing duct is condensed; a cooling water hose for guiding the cooling water to the water supply nozzle; and a cooling water valve for intermitting the flow of the cooling water supplied to the cooling water hose.

Further, preferably, the pumping device may include a drainage bellows connected to the tub for discharging the wash water in the tub; a circulation pump for pumping the discharged wash water to the drainage bellows; and a circulation channel for guiding the wash water pumped by the circulation pump to the inside of the drying device or the inside of the drum.

More preferably, the circulation channel may include a common channel connected to the circulation pump; a drying device connection channel communicating with the common channel; and a drum spray channel communicating with the common channel.

Preferably, the pumping device may further include a wash water circulation control valve for opening and closing the drying device connection channel or the drum spray channel.

The common channel may include a common hose having one end connected to the circulation pump and the other end connected to the wash water circulation control valve.

The drying device connection channel may include a drying device connection hose having one end connected to the wash water circulation control valve and the other end connected to the drying device; and a spray nozzle for spraying the wash water, having passed through the drying device connection hose, to the rear part of the heater so that the wash water is heated by the air heated by the heater.

The drum spray channel may include a drum spray hose having one end connected to the wash water circulation control valve and the other end located in front of the drum; and a spray nozzle connected to the other end of the drum spray hose and provided with an opening facing toward the inside of the drum so that the wash water having passed through the drum spray hose is sprayed to the inside of the drum.

Preferably, the pumping device may include a drainage bellows connected to the tub for discharging the wash water in the tub; a circulation pump for pumping the discharged wash water to the drainage bellows; and a circulation channel for guiding the wash water pumped by the circulation pump to the drying device.

In accordance with yet another aspect of the present invention, there is provided a method for controlling a washing machine having a drying function comprising: turning on a circulation fan and a heater of a drying device in a washing or rinsing mode; and turning on a circulation pump so that wash water in a tub is heated by air having passed through the heater and supplied to the inside of a drum, or is supplied from the front part of the drum to the inside of the drum.

Preferably, a wash water circulation control valve installed on a circulation channel may be controlled in a synchronous mode so that a portion of the wash water pumped by the circulation pump is heated by the air having passed through the heater, and the remainder of the wash water is supplied to the inside of the drum.

Further, preferably, the wash water circulation control valve may be controlled in an alternate mode so that the wash water pumped by the circulation pump is alternately heated by the air having passed through the heater or supplied to the inside of the drum.

The washing machine of the present invention heats the wash water using the heater of the drying device so that washing of laundry at a high temperature is performed without any additional heater for heating the wash water, thereby having low production costs and a simple structure of the tub.

The washing machine of the present invention uniformly sprays the wash water to the inside of the drum without heating as well as pumps the wash water to the inside of the drying device, heats the wash water, and sprays the wash water to the inside of a drum, thereby improving washing and rinsing capacities and decreasing the quantity of the wash water in use.

The washing machine of the present invention comprises the wash water circulation control valve for opening and closing the drying device connection channel or the drum spray channel so that high-temperature washing by means of heating using the heater or washing by means of spraying of the wash water is selected, thereby obtaining optimum washing and rinsing capacities in consideration of kinds of the laundry.

The washing machine of the present invention further comprises the spray nozzle for spraying the wash water to the rear part of the heater, thereby performing steam washing.

The method for controlling the washing machine of the present invention causes a portion of wash water to be heated by air having passed through a heater and the remainder of the wash water to be sprayed to the inside of a drum, or the wash water to be alternately heated by the air having passed through the heater and sprayed to the inside of the drum, thereby simultaneously improving washing and rinsing capacities by means of a high temperature and washing and rinsing capacities by means of the spraying of the wash water.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view of a conventional washing machine having a drying function;

FIG. 2 is an exploded perspective view of a washing machine having a drying function in accordance with a first embodiment of the present invention;

FIG. 3 is a longitudinal sectional view of the washing machine in a washing or rinsing mode in accordance with the first embodiment of the present invention;

FIG. 4 is a longitudinal sectional view of the washing machine in a drying mode in accordance with the first embodiment of the present invention;

FIG. 5 is a block diagram of the washing machine in accordance with the first embodiment of the present invention;

FIG. 6 is a flow chart illustrating a method for controlling the washing machine in accordance with the first embodiment of the present invention;

FIG. 7 is an exploded perspective view of a washing machine having a drying function in accordance with a second embodiment of the present invention;

FIG. 8 is a longitudinal sectional view of the washing machine in accordance with the second embodiment of the present invention; and

FIG. 9 is a block diagram of the washing machine in accordance with the second embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, preferred embodiments of the present invention will be described in detail with reference to the annexed drawings.

FIG. 2 is an exploded perspective view of a washing machine having a drying function in accordance with a first embodiment of the present invention, FIG. 3 is a longitudinal sectional view of the washing machine in a washing or rinsing mode in accordance with the first embodiment of the present invention, and FIG. 4 is a longitudinal sectional view of the washing machine in a drying mode in accordance with the first embodiment of the present invention.

As shown in FIGS. 2 to 4, the washing machine of this embodiment comprises a casing 50 defining an external appearance, a tub 60 installed in the casing 50 for containing wash water (w), a drum 70 rotatably placed in the tub 60 for containing laundry (m), a drying device 80 for drying the laundry (m) in the drum 70, and a pumping device 90 for pumping the wash water (w) in the tub 60 so that the wash water in the tub 60 is circulated into the drum 70 or heated by the air passing through the drying device 80, and is then circulated into the drum 70.

The casing 50 includes a base 52, a cabinet 54 disposed on the base 52 and provided with an opened front surface, a cabinet cover 56 disposed on the front surface of the cabinet 54 and provided with an opening 56A formed therethrough for allowing the laundry to be put into and taken out of the casing 50, and a top cover 58 disposed on the upper surface of the cabinet 54.

A door 56B for opening and closing the opening 56A is rotatably installed on the cabinet cover 56.

The tub 60 is mounted on dampers 61A connected to the base 52, and is supported by the base 52 so that shock applied to the tub 60 can be absorbed, and the tub 60 is suspended from springs 61B connected to the cabinet 54, and is supported by the cabinet 54 such that shock applied to the tub 60 can be absorbed.

The tub 60 is a cylindrical bucket, which is laid horizontally. An opening 62 is formed through the center of the front surface of the tub 60, a water supply device 64 for supplying the wash water (w) or a detergent is connected to one side of the upper part of the tub 60, and the pumping device 90 is connected to one side of the lower part of the tub 60.

The water supply device 64 includes a water supply valve 64B connected to an external hose 64A for intermitting the wash water (w) supplied through the external hose 64A, a water supply hose 64C for guiding the wash water (w) having passed through the water supply valve 64B, a detergent container 64D for containing the detergent so that the detergent is mixed with the wash water (w) guided by the water supply hose 64C, and a water supply bellows tube 64E for guiding the wash water (w) or the detergent discharged from the detergent container 64D to the inside of the tub 60.

A gasket 66, which closely contacts the door 56B when the door 56B is closed for preventing the wash water (w) or the laundry (m) from being separated from the drum 70, is installed on the tub 60.

Further, a motor 68 for rotating the drum 70 is installed on the tub 60.

The motor 68 is installed on the rear surface of the tub 60, and a rotary shaft of the motor 68 for directly rotating the drum 70 passes through the tub 60 and is connected to the rear surface of the drum 70.

The drum 70 is a cylindrical bucket, which is laid horizontally. An opening 72 for allowing the laundry (m) to be put into and taken out of the drum 70 therethrough is formed through the center of the front surface of the drum 70, through holes 74 for circulating the wash water (w) or air therethrough are formed through the circumferential or rear surface of the drum 70, and lifters 76 for lifting the laundry (m) and dropping the laundry (m) are protruded from the inner wall of the drum 70.

The drying device 80 inhales air present in the tub 60 and the drum 70, heats the inhaled air, and circulates the heated air into the drum 70, thereby drying the laundry (m) in the drum 70. The drying device 80 includes a drying duct 83 containing a heater 81 and a circulation fan 82 for discharging hot air to the inside of the tub 60.

The drying device 80 further includes a condensing duct 84 for guiding the air in the tub 60 to the drying duct 83, a water supply nozzle 85 formed at one side of the condensing duct 84 for spraying cooling water to the inside of the condensing duct 84 so that moisture in the air passing through the condensing duct 38 is condensed, a cooling water hose 86 for guiding the cooling water to the water supply nozzle 85, and a cooling water valve 87 for intermitting the cooling water supplied to the cooling water hose 86.

The pumping device 90 circulates the wash water (w) in the tub 60 so that the wash water (w) in the tub 60 is supplied to the inside of the drum 70 or heated by the air passing through the drying device 80, and is then supplied to the inside of the drum 70. The pumping device 90 includes a drainage bellows 91 connected to a drainage of the tub 60 to discharge the wash water (w) in the tub 60.

The pumping device 90 further includes a filter case 93 having a filter 92 for eliminating foreign substances, such as lint, from the wash water discharged through the drainage bellows 91.

The pumping device 90 further includes a circulation pump 94 for pumping the wash water (w) to circulate the wash water (w), and a circulation channel for guiding the wash water (w) pumped by the circulation pump 94.

The circulation pump 94 is installed at one side of the filter case 93 so that the wash water in the filter case 93 is pumped by the circulation pump 94.

The circulation pump 94 includes an impeller for pumping the wash water (w), and a motor unit for rotating the impeller.

The circulation channel includes a common channel connected to the circulation pump 94, a drying device connection channel connected to the common channel, and a drum spray channel connected to the common channel. The circulation channel further includes a wash water circulation control valve 95 for opening and closing the drying device connection channel or the drum spray channel.

The common channel includes a common hose 96 having one end connected to the circulation pump 94 and the other end connected to the wash water circulation control valve 95.

The drying device connection channel includes a drying device connection hose 97 having one end connected to the wash water circulation control valve 95 and the other end connected to the drying duct 83, and a spray nozzle 98 for spraying the wash water (w), having passed through the drying device connection hose 97, to the rear part of the heater 81.

The spray nozzle 98 has a mesh structure for causing the pumped wash water (w) to collide therewith and to be sprayed.

The drum spray channel includes a drum spray hose 99 having one end connected to the wash water circulation control valve 95 and the other end located around the gasket 66 in front of the drum 70, and a spray nozzle 100 connected to the other end of the drum spray hose 99 so that the wash water (w) having passed through the drum spray hose 99 is sprayed to the inside of the drum 80 and installed in the gasket 66 such that the spray nozzle 100 passes through the gasket 66.

The spray nozzle 100 passes through the gasket 66, and is provided with an opening 101 facing toward the drum 70.

The wash water circulation control valve 95 includes an inlet, to which the common hose 96 is connected, a first outlet, to which the drying device connection hose 97 is connected, a valve casing having a second outlet, to which the drum spray hose 99 is connected, a valve unit installed in the valve casing for opening and closing the first or second outlet, and a solenoid for operating the valve unit such that the valve unit opens any one or all of the first and second outlets.

Herein, reference numeral 102 represents a drainage pump installed on the other side of the filter case 93, and reference numeral 104 represents a drainage hose for guiding the wash water (w), pumped by the drainage pump 104, to the outside of the washing machine.

FIG. 5 is a block diagram of the washing machine in accordance with the first embodiment of the present invention.

The washing machine in accordance with this embodiment further comprises an operating unit 110 for inputting operating conditions, such as the washing, rinsing, dehydrating, or drying mode or time, and a control unit 120 for controlling the operations of the motor 68, the water supply valve 64B, the heater 81, the circulation fan 82, the cooling water valve 87, the circulation pump 94, and the wash water circulation control vale 95 based on the input of the operation conditions using the operating unit 110.

Hereinafter, the operation of the above-described washing machine will be described in detail.

FIG. 6 is a flow chart illustrating a method for controlling the washing machine in accordance with the first embodiment of the present invention.

First, after laundry (m) is put into the drum 70, the door 56B is closed, and the washing machine is operated. Then, the washing machine having a drying function is operated in the washing, rinsing, dehydrating, or drying mode based on the operating instructions inputted through the operating unit 110.

When the washing mode is selected, the control unit 120 turns on the water supply valve 64B until the wash water (w) in the tub 60 reaches a designated water level, and turns off the water supply valve 64B when the wash water (w) in the tub 60 reach the designated water level (S1 and S2).

The wash water (w), supplied by the turning-on of the water supply valve 64B, sequentially passes through the water supply hose 64C, the detergent container 64D, and the water supply bellows 64E, and flows to the inside of the tub 60. A portion of the wash water (w) in the tub 60 is contained in the drainage bellows 91, and a great portion of the wash water (w) is contained in the bottom of the inside of the tub 60.

Here, the portion of the wash water (w), which is contained in the bottom of the inside of the tub 60, passes through the opening 72 or the through holes 74 of the drum 70, and flows to the inside of the drum 70, thereby soaking the laundry (m).

After the supply of the wash water (w) is terminated (the water supply valve is turned off) or when the supply of the wash water (w) is progressed, the control unit 120 turns on the motor 68 for a designated time (S3).

When the motor 68 is turned on, the drum 70 is rotated, and the laundry (m) is lifted and dropped by the lifters 76, thereby being washed.

After the supply of the wash water (w) is terminated (the water supply valve is turned off) or when the supply of the wash water (w) is progressed, the control unit 120 turns on the heater 81 and the circulation fan 82 for a designated time (S4).

When the heater 81 and the circulation fan 82 are turned on, the air in the drum 70 or the tub 60 is guided by the circulation fan 82, sequentially passes through the condensing duct 84 and the drying duct 83, is heated by the heater 131, and is then circulated to the inside of the drum 70 through the front part of the drum 70.

The control unit 120 turns on the circulation pump 94 for a designated time together with the turning-on of the heater 81 and the circulation fan 82, controls the wash water circulation control valve 95 such that the wash water circulation control valve 95 is operated in one mode of synchronous and alternate modes (S5).

Here, in the synchronous mode, the drying device connection channel and the drum spray channel are simultaneously opened so that a portion of the pumped wash water is heated by the air having passed through the heater 81 and the remainder of the pumped wash water is sprayed to the inside of the drum 70. On the other hand, in the alternate mode, the drying device connection channel and the drum spray channel are selectively opened at a designated time interval so that the pumped wash water is alternately heated by the air having passed through the heater 81 and sprayed to the inside of the drum 70.

In case that the circulation pump 94 is turned on and the wash water circulation control valve 95 is operated in the synchronous mode, the wash water (w) in the drainage bellows 91 is pumped to the common hose 96 by the circulation pump 94, and the pumped wash water (w) passes through the wash water circulation control valve 95 and is divided into the drying device connection hose 97 and the drum spray hose 99.

A portion of the wash water (w) directed to the drying device connection hose 97 is sprayed to the rear part of the heater 81 through the spray nozzle 98, and the sprayed wash water (w) contacts the air of a high temperature having passed through the heater 81, is heated to steam, is guided together with the air to the front part of the drum 70, and soaks the laundry (m) in the drum 70, thereby washing the laundry (m) in a high-temperature state.

The remainder of the wash water (w) directed to the drum spray hose 99 passes through the spray nozzle 100, is sprayed to the inside of the drum 70, and collides with the laundry (m) in the drum 70, thereby increasing the washing capacity of the laundry (m) and rapidly soaking the laundry (m).

In case that the circulation pump 94 is turned on and the wash water circulation control valve 95 is operated in the alternate mode, the wash water (w) in the drainage bellows 91 is pumped to the common hose 96 by the circulation pump 94, and the pumped wash water (w) is alternately pumped to the drying device connection hose 97 and the drum spray hose 99.

When the wash water (w) is pumped to the drying device connection hose 97, the pumped wash water (w) is sprayed and heated, and soaks the laundry (m) in the drum 70, thereby washing the laundry (m) in a high-temperature state. When the wash water (w) is pumped to the drum spray hose 99, the pumped wash water (w) is sprayed to the inside of the drum 70, thereby increasing the washing capacity of the laundry (m) and rapidly soaking the laundry (m).

After a designated time from the turning-on of the heater 81 and the circulation fan 82 and the turning-on of the circulation pump 94 elapses, the control unit 120 turns off the heater 81 and the circulation fan 82, and turns off the circulation pump 94 (S6).

After a designated time from the turning-on of the motor 68 elapses, the control unit 120 turns off the motor 68 (S7).

After the washing machine having the drying function is operated in the above-described washing mode, the contaminated wash water (w) remains in the bottom of the inside of the tub 70 and in the drainage bellows 91 and the filter case 93. The contaminated wash water (w) is discharged to the outside of the washing machine (S8).

The control unit 120 operates the drainage pump 102 for a designated time, and the contaminated wash water (w) in the bottom of the inside of the tub 70 and in the drainage bellows 91 and the filter case 93 is discharged to the outside of the washing machine through the drainage hose 104.

Thereafter, when the rinsing mode is selected, in the same manner as the washing mode, the control unit 120 supplies the wash water (w), circulates the wash water (w), rotates the drum 70, and controls the water supply valve 64B, the motor 68, the heater 91, the circulation fan 92, the circulation pump 94, the wash water circulation control valve 95, and the drainage valve 102 so that the wash water (w) contaminated by rinsing the laundry (m) is discharged to the outside of the washing machine (S9 to S16).

Here, new wash water (w), which is supplied to the inside of the tub 60, in the same manner as the washing mode, is sprayed and heated to rinse the laundry (m) in the drum 70 in a high-temperature state, or is sprayed to the inside of the drum 70 to increase the washing capacity of the laundry (m) and rapidly soak the laundry (m).

When the dehydrating mode is selected, the control unit 120 rotates the motor 68 at a high speed for a designated time and then turns off the motor 68, the motor 68 rotates the drum 70 at a high speed, and moisture remaining in the laundry (m) is eliminated by centrifugal dehydration (S17, S18, and S19).

Further, the control unit 120 operates the drainage pump 102, and the drainage pump 102 discharges the wash water obtained by dehydrating the laundry (m) to the outside of the washing machine (S20).

When the drying mode is selected, the control unit 120 turns on the motor 68 for a designated time (S21 and S22).

When the motor 68 is turned on, the drum 70 is rotated, and the laundry (m) in the drum 70 is lifted and dropped by the lifters 76 of the drum 70.

During the turning-on of the motor 68, the control unit 120 turns on the heater 81 and the circulation fan 82 for a designated time, and turns on the cooling water valve 87 (S23).

When the cooling water valve 87 is turned on, the cooling water having passed through the cooling water hose 86 flows down to the inside of the condensing duct 84 through the cooling water nozzle 85.

When the heater 81 and the circulation fan 82 are turned on, the air in the drum 70 and the tub 60 passes through the condensing duct 84 and is condensed by the cooling water so that the air has a low humidity, and passes through the drying duct 83 and is heated by the heater 81 so that the air has a high temperature and a low humidity. Then, the air is circulated into the drum 70, thereby drying the laundry (m) in the drum 70.

After a designated time from the turning-on of the heater 81 and the circulation fan 82 elapses, the control unit 120 turns off the heater 81, the circulation fan 82, and the cooling water valve 87 (S24).

Further, after a designated time from the turning-on of the motor 68 elapses, the control unit 120 turns off the motor 68 (S25).

The control unit 120 operates the drainage pump 102, and the drainage pump 102 discharges the condensed water obtained by passing through the condensing duct 84 and the wash water flowing down along the cooling water nozzle 85 to the outside of the washing machine (S26).

FIG. 7 is an exploded perspective view of a washing machine having a drying function in accordance with a second embodiment of the present invention, FIG. 8 is a longitudinal sectional view of the washing machine in accordance with the second embodiment of the present invention, and FIG. 9 is a block diagram of the washing machine in accordance with the second embodiment of the present invention.

As shown in FIGS. 6 and 7, the washing machine of this embodiment comprises a pumping device 130 for circulating the wash water (w) in the tub 60 so that the wash water (w) in the tub 60 is heated by air passing through the drying device 80 and is then circulated into the drum 70. Since the configurations-and functions of the casing 50, the tub 60, the drum 70 and the drying device 80 of the washing machine of this embodiment except for the pumping device 130 are the same as those of the washing machine of the first embodiment, these parts of the washing machine of this embodiment has the same reference numerals as those of the washing machine of the first embodiment, and the detailed descriptions thereof will thus be omitted.

The pumping device 130 includes a drainage bellows 131 connected to a drainage of the tub 60 for discharging the wash water (w) in the tub 60.

The pumping device 130 further includes a filter case 133 having a filter 132 for eliminating foreign substances, such as lint, from the wash water (w) discharged through the drainage bellows 131.

The pumping device 130 further includes a circulation pump 134 for pumping the wash water (w) to circulate the wash water (w), and a circulation channel for guiding the wash water (w) pumped by the circulation pump 134 to the drying device 80.

The circulation pump 134 is installed at one side of the filter case 133 so that the wash water (w) in the filter case 133 is pumped by the circulation pump 134.

The circulation pump 134 includes an impeller for pumping the wash water (w), and a motor unit for rotating the impeller.

The circulation channel includes a drying device connection hose 137 having one end connected to the circulation pump 134 and the other end connected to the drying duct 83 of the drying device 80, and a spray nozzle 138 for spraying the wash water (w), having passed through the drying device connection hose 137, to the rear part of the heater 81 of the drying device 80.

The spray nozzle 138 has a mesh structure for causing the pumped wash water (w) to collide therewith and to be sprayed.

Hereinafter, the operation of the above-described washing machine will be described in detail.

First, in the washing or rinsing mode, the control unit 120 turns on the motor 68, turns on the heater 81 and the circulation fan 82 of the drying device 80, and turns on the circulation pump 134 so that the wash water (w) in the tub 60 is heated by the air having passed through the heater 81.

When the motor 68 is turned on, the drum 70 is rotated, and the laundry (m) in the drum 70 is lifted and dropped by the lifters 76, thereby being washed.

When the heater 81 and the circulation fan 82 are turned on, the air in the drum 70 or the tub 60 is guided by the circulation fan 82, sequentially passes through the condensing duct 84 and the drying duct 83, is heated by the heater 131, and is then circulated to the inside of the drum 70 through the front part of the drum 70.

When the circulation pump 134 is turned on, the wash water (w) having passed through the drainage bellows 131 is pumped to the drying device connection hose 137 by the circulation pump 134, the pumped wash water (w) is sprayed to the inside of the drying duct 84 by the spray nozzle 138, and the sprayed wash water (w) contacts the air in the drying duct 84 heated by the heater 131 so that the sprayed wash water (w) is heated to a high temperature and changed to steam, and is then sprayed to the inside of the drum 70 through the front part of the drum 70.

The wash water (w) of a high temperature sprayed to the inside of the drum 70 directly soaks the laundry (m), thereby washing or rinsing the laundry (m) in a high-temperature state.

After the washing machine having the drying function of this embodiment is operated in the washing or rinsing mode, the washing machine is operated in the dehydrating and drying modes. The dehydrating and drying modes of the washing machine of this embodiment are the same as those of the washing machine of the first embodiment, and the detailed descriptions thereof will thus be omitted.

As apparent from the above description, the present invention provides a washing machine having a drying function, which heats wash water using a heater of a drying device so that washing of laundry in a high-temperature state is performed without any additional heater for heating the wash water, thereby having low production costs and a simple structure of a tub.

The washing machine of the present invention uniformly sprays the wash water to the inside of the drum without heating as well as pumps the wash water to the inside of the drying device, heats the wash water, and sprays the wash water to the inside of a drum, thereby improving washing and rinsing capacities and decreasing the quantity of the wash water in use.

The washing machine of the present invention comprises a wash water circulation control valve for opening and closing a drying device connection channel or a drum spray channel so that high-temperature washing by means of heating using the heater or washing by means of spraying of the wash water is selected, thereby obtaining optimum washing and rinsing capacities in consideration of kinds of the laundry.

The washing machine of the present invention further comprises a spray nozzle for spraying the wash water to the rear part of the heater, thereby performing steam washing.

The present invention further provides a method for controlling a washing machine having a drying function, in which a portion of wash water is heated by air having passed through a heater and the remainder of the wash water is sprayed to the inside of a drum, or the wash water is alternately heated by the air having passed through the heater and sprayed to the inside of the drum, thereby simultaneously improving washing and rinsing capacities by means of a high temperature and washing and rinsing capacities by means of the spraying of the wash water.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. A washing machine having a drying function comprising: a tub for containing wash water; a drum rotatably placed in the tub for containing laundry, and provided with through holes for circulating the wash water or air therethrough; a drying device provided with a circulation fan and a heater for drying the laundry in the drum; and a pumping device for pumping the wash water in the tub so that the wash water in the tub is circulated into the drum, or is heated by the air passing through the drying device and circulated into the drum.
 2. The washing machine as set forth in claim 1, wherein the drying device includes: a drying duct containing the heater and the circulation fan for discharging hot air to the inside of the tub; a condensing duct for guiding the air in the tub to the drying duct; a water supply nozzle for spraying cooling water to the inside of the condensing duct so that moisture in the air passing through the condensing duct is condensed; a cooling water hose for guiding the cooling water to the water supply nozzle; and a cooling water valve for intermitting the flow of the cooling water supplied to the cooling water hose.
 3. The washing machine as set forth in claim 1, wherein the pumping device includes: a drainage bellows connected to the tub for discharging the wash water in the tub; a circulation pump for pumping the discharged wash water to the drainage bellows; and a circulation channel for guiding the wash water pumped by the circulation pump to the inside of the drying device or the inside of the drum.
 4. The washing machine as set forth in claim 3, wherein the circulation channel includes: a common channel connected to the circulation pump; a drying device connection channel communicating with the common channel; and a drum spray channel communicating with the common channel.
 5. The washing machine as set forth in claim 4, wherein the pumping device further includes a wash water circulation control valve for opening and closing the drying device connection channel or the drum spray channel.
 6. The washing machine as set forth in claim 5, wherein the common channel includes a common hose having one end connected to the circulation pump and the other end connected to the wash water circulation control valve.
 7. The washing machine as set forth in claim 5, wherein the drying device connection channel includes a drying device connection hose having one end connected to the wash water circulation control valve and the other end connected to the drying device.
 8. The washing machine as set forth in claim 7, wherein the drying device connection channel further includes a spray nozzle for spraying the wash water, having passed through the drying device connection hose, to the rear part of the heater so that the wash water is heated by the air heated by the heater.
 9. The washing machine as set forth in claim 8, wherein the spray nozzle has a mesh structure for causing the wash water to collide therewith and to be sprayed.
 10. The washing machine as set forth in claim 5, wherein the drum spray channel includes a drum spray hose having one end connected to the wash water circulation control valve and the other end located in front of the drum.
 11. The washing machine as set forth in claim 10, wherein the drum spray channel further includes a spray nozzle connected to the other end of the drum spray hose and provided with an opening facing toward the inside of the drum so that the wash water having passed through the drum spray hose is sprayed to the inside of the drum.
 12. A washing machine having a drying function comprising: a tub for containing wash water; a drum rotatably placed in the tub for containing laundry, and provided with through holes for circulating the wash water or air therethrough; a drying device provided with a circulation fan and a heater for drying the laundry in the drum; and a pumping device for pumping the wash water in the tub so that the wash water in the tub is heated by the air passing through the drying device, and is then circulated into the drum.
 13. The washing machine as set forth in claim 12, wherein the drying device includes: a drying duct containing the heater and the circulation fan for discharging hot air to the inside of the tub; a condensing duct for guiding the air in the tub to the drying duct; a water supply nozzle for spraying cooling water to the inside of the condensing duct so that moisture in the air passing through the condensing duct is condensed; a cooling water hose for guiding the cooling water to the water supply nozzle; and a cooling water valve for intermitting the flow of the cooling water supplied to the cooling water hose.
 14. The washing machine as set forth in claim 12, wherein the pumping device includes: a drainage bellows connected to the tub for discharging the wash water in the tub; a circulation pump for pumping the discharged wash water to the drainage bellows; and a circulation channel for guiding the wash water pumped by the circulation pump to the drying device.
 15. The washing machine as set forth in claim 14, wherein the circulation channel includes a drying device connection hose having one end connected to the wash water circulation control valve and the other end connected to the drying device.
 16. The washing machine as set forth in claim 15, wherein the circulation channel further includes a spray nozzle for spraying the wash water, having passed through the drying device connection hose, to the rear part of the heater so that the wash water is heated by the air heated by the heater.
 17. The washing machine as set forth in claim 16, wherein the spray nozzle has a mesh structure for causing the wash water to collide therewith and to be sprayed.
 18. A method for controlling a washing machine having a drying function comprising: turning on a circulation fan and a heater of a drying device in a washing or rinsing mode; and turning on a circulation pump so that wash water in a tub is heated by air having passed through the heater and supplied to the inside of a drum, or is supplied from the front part of the drum to the inside of the drum.
 19. The method as set forth in claim 18, wherein a wash water circulation control valve installed on a circulation channel is controlled in a synchronous mode so that a portion of the wash water pumped by the circulation pump is heated by the air having passed through the heater, and the remainder of the wash water is supplied to the inside of the drum.
 20. The method as set forth in claim
 19. wherein a wash water circulation control valve installed on a circulation channel is controlled in an alternate mode so that the wash water pumped by the circulation pump is alternately heated by the air having passed through the heater or supplied to the inside of the drum. 